Not all new discoveries in biodiversity happen in the wild places. In this guest post from Stéphanie Boucher, Curator of the Lyman Museum, we meet two little surprises from an urban backyard garden in the middle of Montreal.
Phytomyza petoei (Order Diptera, Family Agromyzidae)
If you grow cultivated mint in your garden and you notice mines on the leaf, they are probably caused by a fly larva from the family Agromyzidae, best known as the leaf miner flies. Although many people would not have paid much attention to the leaf damage in the photo below, it turned out to be a very interesting discovery.
Some of the mined leaves were collected so the flies could be reared (although the shape of mines is often distinctive, adult flies are necessary to confirm the identity of the species). The flies were identified as Phytomyza petoei, a species that was known from Europe but had never been recorded in North America until these specimens were collected in 2008 (see Boucher 2009 under Publications). The presence of this species in North America is noteworthy because of its potential to be a pest on cultivated mint. The species feeding on your backyard mint is probably this species. The only other Nearctic species of Agromyzidae known to feed on mint is Calycomyza menthae, a species with apparently no economic importance and recorded only on wild mint (Mentha arvensis). In contrast, larvae of Phytomyza petoei can occur in considerable numbers on cultivated mint, although not enough to affect the growth of the plant. So far confirmed only from Montreal, this species may be more common and widespread in Canada and possibly the United States than is currently known.
Acanalonia conica (Order Hemiptera: Family Acanaloniidae)
This pretty bright green insect measuring about 1 cm long was photographed in October 2011, in the same Montreal garden. This photo is the first record of this species in Quebec. Although Acanalonia conica is widely distributed in the eastern United States (from Nebraska and Texas eastward), it is quite rare and restricted in Canada, having been recorded previously only from southern Ontario. This Nearctic species was also recently recorded in Europe (Italy). Like other homopterans it feeds on the sap of plants. Not picky at all in its choice of hosts, it will feed on a wide range of wild and cultivated plants including trees, shrubs and grasses from multiple families. The female lays eggs in woody plant tissues in late summer and fall. There is only one generation a year. September is a good time to observe this insect as the females are looking for good spots to lay their eggs. Although small, the bright green color, unstriped broad wings with irregular reticulate venation, and the pointy head should help you identify the insect. Keep an eye out for it!