Natural history of Corythucha juglandis and Gargaphia tiliae (Hemiptera: Tingidae) in Ontario and Québec, Canada

Abstract

The natural history of Corythucha juglandis (Fitch) and Gargaphia tiliae (Walsh) (Hemiptera: Tingidae) was studied in Ontario and Québec, Canada. These univoltine species overwinter as adults in leaf litter in a state of reproductive diapause and become active in April or May. They are specific to their host plants. Adults, eggs, and nymphs of both species were collected from the underside of leaves of host plants. The reproductive systems of both male and female, as well as eggs, nymphs, and operculum of the eggs of the two species, are described and illustrated. Fecundity, incubation period, development of nymphs, feeding, mating, and oviposition were studied. Mating was end-to-end at an angle of 35–40°. The reproductive potential, oviposition pattern, and site selection in the two species were investigated. Parental care of eggs and brood of G. tiliae is also reported and illustrated. Ocelli, true spermathecae, true egg micropyles, and true egg burster are absent in the two species. Fertilisation takes place before chorion formation. Adults, nymphs, and new generation aggregate on the underside of leaves of their host or nearby deciduous plants. In October they fly a short distance to overwintering sites within leaf litter.

Natural history of Dictyla echii (Hemiptera: Tingidae) in Ontario and Québec, Canada

“…Females mated 3–5 times; the mating position in D. echii is side to side with last abdominal segment at approximately a 35–40° angle from the substrate. This is similar to that of Corythucha juglandis (Fitch) (Hemiptera: Tingidae), which was described by Javahery (2019). Adults of the new generation leave the breeding sites after the host becomes dried in late August and in September.…”

“…Mating position in Heteroptera is usually end-to-end (Javahery 1995), although mating is side-by-side or lateral in orientation in a few species (Javahery 2013). However, in D. echii and the two Tingidae ( Corythucha juglandis (Fitch) and Gargaphia tiliae (Walsh)), mating was at an angle of about 30–45° (Javahery 2019).…”