Introduction
Neuroptera: from the Greek neuron = a nerve, and ptera = wings.
Small to medium sized insects, 2 to 120 mm long. Body form and appearance quite varied. Head prognathous with mandibulate mouthparts. Lacking ocelli in families in British Columbia. Prothorax usually short, and shorter than combined length of the mesothorax and metathorax. If prothorax long, then forelegs raptorial. Forewings and hindwings membranous, equal or subequal in size and narrowed at base, and held roof-like over the abdomen when at rest. Venation, if not reduced, with main longitudinal veins branched at wing margins, and wings with many cross-veins. If venation reduced, then insects either covered with a whitish powder (Aleyrodidae) or with an elongate pronotum and raptorial forelegs (Mantispidae). Legs usually cursorial, except in Mantispidae. Abdomen without cerci, and usually without a long ovipositor in the female (except in the Mantispidae).
Adults are primarily, but not exclusively crepuscular or nocturnal. They may have complex courtship and mating rituals.
Larvae are predaceous, usually with piercing and sucking mouthparts. Most spin silken cocoons.
Worldwide there are some 17 families, eight of which occur in British Columbia.
Key to families
1. | Wings with few veins and less than 10 closed cells; small to minute insects covered with white exudate | |
- | Wings with numerous veins, and more than 10 closed cells; body without white exudate |
2
|
2. | Forelegs raptorial; prothorax elongate | |
- | Forelegs not raptorial; prothorax subquadrate or slight longer than broad |
3
|
3. | Antennae clubbed | |
- | Antennae not clubbed, but filiform, moniliform, or pectinate |
4
|
4. | Wings with numerous crossveins between vein R1 and RS, or R5 arising from 2 or 3 stems |
5
|
- | Wings with 1 to 4 crossveins between R1 and RS |
6
|
5. | Forewings with some costal crossveins bifurcate; body and wings usually brown | |
- | Forewings without bifurcate costal crossveins; body and wings green or brown | |
6. | Forewings with about 15 parallel branches of RS; wingspan at least 40 mm | |
- | Forewings with 4 to 7 branches of RS; wingspan less than 30 mm |
7
|
7. | Forewings with some costal crossveins bifurcate; gradate vein present | |
- | Forewing without bifurcate crossveins; graduate vein absent |
Description of Families
Family Berothidae (Beaded Lacewings) (Fig.
5)
Small to medium sized insects, with 15 to 30 mm wingspans. Head with moniliform
antennae. Prothorax short, and forelegs simple and not raptorial in Nearctic
species. Forewings falcate, with concave outer margin. The wing venation of
the forewing has only a simple radial sector, with all branches of radial sector
arising from the fourth vein. There are one to four crossveins between R1 and
R5. The costal vein is simple, with some costal crossveins bifurcate. The humeral
crossvein is simple, and a graduate vein is present. Females characteristically
have seed-like scales and long setae on the wings, usually with encrusted secretions
on the setae. Scales are never present in males, which have an intricately coiled,
protrusible intromittant organ within the abdomen.
Females lay stalked eggs on wood surfaces, often near wood termite nests. Larvae are inquilines in dry wood termite and ant nests, where they feed by injecting a paralyzing chemical into the termite or ant prey, and then suck out the body fluids of the immobilized insects.
Worldwide there are 25 genera and 57 described species, distributed throughout the warmer regions of the world. The family is very diverse in Australia, with six genera and 19 species.
There is only one genus Lomamyia in North America, with 10 described species, all of them relatively rare and little known. Only one western Nearctic species, L. occidentalis (Banks) occurs in Canada, restricted to British Columbia. It is only known from the Lytton area and Penticton.
Family Chrysopidae (Green
Lacewings) (Figs. 6
& 7)
As the common name implies, most chrysopid adults are green with golden eyes.
However, some genera are predominately brown or black. Green lacewings usually
have red or dark markings, and the green colouration usually fades soon after
death. Adults are 10 to 25 mm long, with long and filiform antennae. The prothorax
is short, and the forelegs non-raptorial. The forewings lack bifurcating costal
crossveins, and the humeral crossvein is simple. There are numerous crossveins
between veins R1 and R5, or R5 arises from two or three stems. The wing cells
are glassy transparent, and without microtrichia.
Adults have a clumsy flight, and are often attracted to light at night. Many species can produce a noxious smelling fluid from their prothoracic glands. Mating is nearly always preceded or accompanied by abdominal vibrations, and this courtship song is species specific. Members of the subfamily Chrysopinae characteristically have a tympanal receptor for detecting the ultrasound signals of bats, so are somewhat protected from bat predation.
Adults lay stalked eggs singly on vegetation, and larvae are active, searching predators, especially on aphids. Most exhibit trash-carrying behaviour, which is accomplished by having dorsolateral setigerous tubercles and hooks, and glandular setae on the body. Most larvae are associated with plants, but a few species live in terrestrial leaf litter. When mature, larvae spin a compact, very closely woven silky cocoon, that may incorporate debris and broken setae in the trash-carrying forms.
Recently, in may parts of the world, green lacewings, particularly members of the Chrysoperla carnea-group, have been used in biological control of plant lice on agricultural crops. While most species of green lacewing can readily be recognized and identified by colour pattern and markings, wing venation, and genitalia characteristics, there are a number of cryptic species in the genus Chrysoperla that are morphologically indistinguishable, but really are good biological species as judged by their mating behaviour and courtship songs. Of course, such sibling species cannot be identified from dead and preserved specimens. Without having live sexually receptive insects, it is not possible to recognize these species. Furthermore, it is now known that there is convergent evolution of courtship songs among many of the species in the Chrysoperla carnea-group. Thus, in this account, the C. carnea-group is considered as a single entity, namely C. carnea (Stephens) sensu lat.
Worldwide the family Chrysopidae contains 75 genera and about 1200 species. Identification of some of the genera depends on genitalia characters, this requiring dissection. The North American fauna consists of 15 genera and 81 described species, of which nine genera and 24 species are listed for Canada. So far, seven genera and 17 species are recorded from British Columbia, if the Chrysoperla carnea-group is taken to be a single species. Eight of the Canadian species occur only in British Columbia, five being rare.
The composition of the British Columbia chrysopid fauna is Chrysopa (7 sp.), Chrysoperla (1 sp.), Dichrochrysa (1 sp.), Eremochrysa (2 sp.), Meleoma (4 sp.), Nineta (1 sp.) and Nothochrysa (1 sp.). Eremochrysa punctinerius (McLachlan), Dichrochrysa perfecta (Banks), and Meleoma schwarzi (Banks) known only from the southern interior, or the South Okanagan in the case of the latter two species, are regarded as rare. Likewise, Nineta granda (Banks) and Nothochrysa californica Banks, confined to Vancouver Island in the case of the former, and Vancouver Island, the Gulf Islands and the lower mainland in the case of the latter, are also rare.
Family Coniopterygidae
(Dustywings) (Fig.
9)
Very small, 2 to 3 mm long, slender pale insects, with legs, wings and body
covered with whitish or light greyish powder, secreted by hypodermal glands
in the terga and sterna. Head hypognathous, with relatively large eyes, but
lacking ocelli. Antennae filiform with from 16 to 57 segments.
Prothorax weakly sclerotized, pterothorax well sclerotized. Wings with venation reduced, consisting of few longitudinal veins and crossveins. Costa of forewing much reduced and visible only at its base. Subcosta running parallel with fore margin distally furcate, with posterior branch resembling a crossvein, and apically looking like terminal part of radius. Radial sector at most forking once. Wing-coupling involving hamuli-like hooks. Legs slender with 5-segmented tarsi. The abdomen is only weakly sclerotized.
Adults are quite active around dawn and dusk, but have a low dispersal ability, although they are fairly long-lived. They are mostly found on bushes or trees, and some are associated with particular types of vegetation or even single species of bush or tree, such as conifers. Some are attracted to light.
Eggs are laid usually singly, but sometimes in twos or threes, on bark or leaves. The larvae are fusiform in shape, widest anteriorly. They have straight, needle-like jaws, and like the adults feed on adults and larvae of small, relatively inactive arthropods, such as aphids, scale insects, and mites. They thus may be useful in the biological control of such invertebrates.
Worldwide there are 23 genera and 423 described species, with these insects occurring in all regions of the world. So far eight genera and 55 species are reported in North America, with four of these genera and 10 species known from Canada. To date, four genera and eight species have been recorded from British Columbia, namely Conipteryx (2 sp.), Conwentzia (3 sp.), Helicoconis (2 sp.) and Semidalis (1 sp.). Five species, Conwentzia californica Meinander, C. psociformis (Curtis), Helicoconis californica Meinander, H. similis Meinander, and Semidalis angusta (Banks), in Canada only occur in British Columbia. At the moment, Helicoconis similis is listed as endemic, known only from the top of Moyie Mountain in the Kootenays.
Family Hemerobiidae (Brown
Lacewings) (Fig.
10 & 11)
Adults, typically 6 to 12 mm long (rarely 2 to 3 mm), are predominantly brown
or blackish in colour, although some species appear golden or even iridescent.
The head possesses filiform antennae and the prothorax is short. The forelegs
are non-raptorial. The wings are usually rather broad, and the forewings typically
have some costal crossveins bifurcate. Veins R5 and MA characteristically are
fused with R in the forewing to give the appearance of having multiple radial
sectors.
Adults are largely crepuscular or nocturnal, often attracted to light. They are mostly associated with trees or bushes, where they feed on aphids, mealy bugs and mites. Eggs are unstalked and laid in small batches. The larvae are elongate, small-headed, and lack prominent setose tubercles. They are to be found on trees and low herbage, preying on the same food as the adult. When mature they pupate having formed a loosely constructed, double-walled cocoon.
Worldwide there are about 80 genera and over 800 described species. So far six genera and 61 species have been reported in North America, with all six genera and 41 of these species known to occur in Canada. So far all six North American genera are known from British Columbia, containing 33 species, six of which are confined to this province. The provincial fauna consisting of Hemerobius (13 species), Megalotomus (two species), Micromus (seven species) is little studied, but at least four species in the Okanagan, namely Micromus subanticus (Walker), Sympherobius californicus Banks, S. killingtoni Carpenter, and Wesmaelius pretiosa (Banks) appear to be rare.
Family Mantispidae (Mantidflies)
(Fig.
12 & 13)
Mantidflies are distinctive, medium-sized insects (about 15 to 25 mm long in
BC), often with colourful bodies and sometimes with marked wings. The most striking
features are the mantid-like extension of the prothorax and the enlarged, raptorial
forelegs. The head is mantid-like and triangular when viewed from the front,
with the large eyes well separated. The antennae consist of many bead-like segments
and are shorter than the prothorax. The ratio of least width to greatest width
of the prothorax (in Canadian species) ranges from about 0.1 to 0.4. In the
foreleg the coxa is enlarged and is at least as long as the swollen, spined
femur; the tibia is curved, fitting tightly against the femur. The mid and hind
legs are slender and unmodified. Unlike those of the mantids, the fore and hind
wings are similar in size, shape and texture.
Adults of the Mantispidae, as their name suggests, resemble the mantids of the Order Mantodea. However, the two groups are only distantly related in the Insecta, the superficial resemblance is the result of convergent evolution. There are many differences, the most obvious is that mantispids have a pupal stage while the mantids do not. The adults are predators of other small insects. Canadian mantispid species belong to the Subfamily Mantispinae, whose larvae all apparently develop by feeding on spider eggs. The biology of most other mantispids is more poorly known, but at least some retain the original larval habit of general predation. Clutches of about 200 to 2000 stalked eggs are laid on leaves, branches and other objects. In the Mantispinae, the first stage larvae are active and find spider eggs by searching for, and penetrating, egg sacs or by boarding a female spider and entering the egg sac as it is constructed. In some species studied, one of these two behaviours is obligatory, although in two species known from eastern Canada, Dicromantispa sayi (Banks) and D. interrupta (Say), apparently either is possible. The larvae of the two BC species, Climaciella brunnea (Say) and Leptomantispa pulchella (Banks), board spiders and feed on their blood before entering the egg sacs. Climaciella usually attacks lycosid spiders; Leptomantispa boards spiders of several families, but mostly anyphaenids and salticids. Once inside the egg case, which is its sole source of food during development, the larva becomes grub-like. When feeding and growth is complete, pupation occurs inside the egg case.
The Mantispidae is a small family of about 488 described species in 39 genera world wide. About 15 species are recorded in North America; two of these live in BC -- Climaciella brunnea (Say) and Leptomantispa pulchella (Banks). The former species is the more widespread in the province, ranging across the southern lowlands from Vancouver Island to the East Kootenays. It is also recorded east to Quebec and south to Costa Rica. In BC Climaciella is usually collected in grasslands or in the edges of dry Douglas-fir or Ponderosa Pine forests. The adult is patterned in brown, yellow and black; the front halves of the wings are brown. The similarity of its coloration is to that of the paper wasp. Polistes fuscatus is striking. The mantispid is probably a mimic of the wasp; in BC, at least, the ranges of the two insects are almost identical. Leptomantispa pulchella ranges from the Okanagan Valley of BC and extreme southern Ontario over much of the United States and south to Costa Rica. It is smaller and more delicate than Climaciella. Its body is yellow with black or brown markings; the wings are clear except for the orange pterostigma. Leptomantispa has seldom been collected in BC; it has usually been found in or near Ponderosa Pine woods.
Family Myrmeleontidae (Ant-lions)
(Fig.
14)
Medium to large insects, 35 to 80 mm long, somewhat resembling damselflies.
However, the antennae are short, about as long as the combined length of the
head and thorax, and with a distinct, clubbed apex. The head lacks ocelli, the
pronotum is short and broad, and the forelegs are not raptorial. The wings are
narrowly elongate, transparent or mottled with brown or black. They have many
crossveins and branches along the margin. Typically the wings usually have an
elongate, narrow cell immediately behind the point of coalescence of veins.
Sc and R1. The abdomen is long and thin.
Adults have a weak, fluttering flight, and are thought to feed on small insects. Although some are day-active, most are crepuscular or nocturnal, and frequently come ot light at night. Courtship and mating of adults evidently has never been described. Eggs apparently are laid singly, in soil or sand.
As a whole, the larvae in this family are quite variable in form and habit, but all have powerful curved jaws. The larvae of some tribes in the subfamily Myrmeleontinae, are the familiar “ant-lions”, that excavate conical pitfall traps for catching ants. Such larvae have a narrow dished head, and a peculiar vertically oriented neck area, both adaptations for throwing sand up and out of pits during their construction or for prey capture. Other larvae, that do not form pitfall traps, live under or on the soil surface, in debris, rock crevices, caves or tree-holes. Pupation occurs in sand or soil, inside spherical cocoons.
Worldwide there are 201 described genera and 1522 species. These occur in all the warmer, drier regions of the world, but also can be found in moist, forested regions. So far 17 genera and 93 species are known from North America, with four genera and six species reported from Canada. Brachynemurus abdominalis (Say), the commonest species in British Columbia, is found throughout the southern interior, and is also known from Manitoba and Ontario. The only other species in eastern Canada, reported only from Ontario is B. nebulosus (Olivier). The other four species in British Columbia, namely Brachynemurus ferox (Walker), Dendroleon speciosus Banks, Myrmeleon exitialis Walker, and Scotoleon pregrinus (Hagen) are confined to this province in Canada. All four occur in the southern interior, with Dendroleon speciosus and Myrmeleon exitialis also known from Vancouver Island, the latter being the commonest here and on the Gulf Islands.
Family Polystoechotidae
(Giant Lacewings) (Fig.
15)
Large and distinctive lacewings, with wingspan from 35 to 75 mm. The head has
long, filiform antennae, but no ocelli. The prothorax is short, but broad, and
the forelegs are not raptorial. The wings are dusky with the costal and marginal
areas provided with many forked veinlets. The humeral crossvein is recurrent
and branched. The forewing characteristically has the subcosta (Sc) fused to
R1 apically, and the wings have only one discal and one marginal series of distinct
gradate veins.
Adults are predaceous and nocturnal, often attracted to light. However, little else is know about their biology. The larvae are evidently terrestrial and predaceous.
The family is confined to the New World, with only three described monotypic genera, namely Fonticelia from Chile, Platystoechotes from California, and Polystoechotes known from across temperate North America and as far south as Panama. Polystoechotes punctatus (Fabricius) occurs in Alaska, and in Canada is known from Alberta, British Columbia, Ontario, and Quebec. In BC it occurs on Vancouver Island and across most of the mainland.
Family Sisyridae (Spongilla-flies)
(Fig.
16)
Adults are very similar to brown lacewings, and are 6 to 8 mm long. The head
has long filiform antennae, and lacks ocelli. The prothorax is short and broad,
and the forelegs are not raptorial. The wings are broad with relatively few
crossveins, and with cells translucent and with microtrichia. The forewings
have only a few elongate radial and medial cells, and there is a small enlargement
or expansion of the marginal vein between the ends of the veins. A gradate vein
is absent.
Adults usually occur in late summer, and although frequently found near freshwater, can occur at light often far from water. Eggs are laid in small clusters above water, and larvae fall directly into water on hatching. The aquatic larvae live in and feed on freshwater sponges. They have very elongate and rather thin sucking jaws, which are very flexible and able to probe and suck out contents of cells of sponges. Second and third instar larvae have seven pairs of segmented, transparent, ventral abdominal gills for respiration. The legs are slender and always have a single claw. The first instar larvae lack gills. When matured and ready to pupate, larvae leave the water and spin a double silk cocoon on a three trunk, or some other object near the water.
Worldwide there are three genera and 48 described species. The genus Climacia is confined to the New World and contains 11 species. Sisyra is cosmopolitan with 34 described species, while Sisyrina with just three species occurs in Africa, Asia, and Australia. The two genera, Climacia and Sisyra that occur in North America, occur in Canada. Although six species are known from North America, only three occur in Canada, with Climacia areolaris (Hagen) known only from Ontario and Quebec. The other two species, Sisyra fuscata (Fabricius) and S. vicaria (Walker) also occur in British Columbia.