Effects of short‐term heat stress on the growth and development of Bradysia cellarum and Bradysia impatiens

Abstract

Bradysia cellarum Frey and Bradysia impatiens Johansen are major pests of vegetable crops, as well as edible mushrooms and ornamental plants, and damage to hosts resulting in economic losses. Temperatures above the optimum levels for these pests have been predicted to regulate their population growth during summer. The aim of the present study was to examine the effects of both heat stress and exposure time on the growth and development of eggs, larvae and pupae for two Bradysia species. The egg stage, egg hatching rate, 4th instar larval stage, pupation rate, pupal stage and adult emergence rate were observed after exposing at high temperatures of 34°C, 37°C and 40°C for 1, 2, 4 and 6 hr. The results showed that 34°C, 37°C and 40°C for 1‐, 2‐, 4‐ and 6‐hr exposure treatments prolonged the developmental stage of egg, 4th instar larva and pupa, while decreasing the egg hatching rate, pupation rate and adult emergence rate. This suggests that increasing temperature or prolonging exposure time to the heat stress could significantly affect insect survival, growth and development. Our study could provide an ecological basis for pests’ management strategy by using short‐term heat stress.

Effects of Aqueous Extracts of Endophyte-Infected Grass Achnatherum inebrians on Growth and Development of Pea Aphid Acyrthosiphon pisum

“…A total of 2700 adult (10 adult × 3 growth periods × 3 treatments × 30 replicates) were used with three growth periods (seeding stage, maturity, yellow stage), three treatments (E+, E−, CK), thirty replicates (30 replicates of different leaves) for pea aphid of green and red color morphs, respectively. The adult pea aphids on these leaves were considered the F 0 population, and pea aphids were regarded to be dead when no movements were observed after being lightly touched on the hind legs [ 27 , 28 , 29 ]. For numbers of dead adult pea aphids were recorded after exposures for 24 h, 48 h and 72 h.…”

Artificial Diet Influences Population Growth of the Root Maggot Bradysia impatiens (Diptera: Sciaridae)

“…The hatched larvae from these eggs were reared on the same diet sequentially. Freshly emerged adults, male and female were transferred to individual transparent plastic containers (15 × 9 cm) moistening with filter paper and paired with a 1:1 = male:female ratio ( Gou et al 2020a ). If the number of males emerged was less than the females on a given day in any treatment, then males from an extra set of insects reared in parallel at the respective artificial diet were used.…”

Effects of four constant temperatures on the development of two Bradysia (Diptera: Sciaridae) species

“…The responses of B. odoriphaga and B. impatiens to high temperatures have been reported (Gou, Guo, Wang, et al, 2020;Zhu et al, 2018). But previous studies focused mostly on lethal and sublethal short-term heat shocks and lacked the whole generation observations under constant high temperature exposure (Luo et al, 2017;Shi et al, 2020;Zhu et al, 2017Zhu et al, , 2018.…”

“…Cheng et al reported negative effects of high temperatures (31, 33, 35 and 37°C) and exposure times (from 0 min to 120 min) on the survival, fecundity and offspring development of B. odoriphaga (Cheng et al, 2017). Gou et al reported that when exposed to a heat shock for 2 hr at 40°C, the eggs, larvae and pupae of B. odoriphaga and B. impatiens all died (Gou, Guo, Wang, et al, 2020). Zhu et al, (2017) revealed that the survival rate, longevity and oviposition of B. odoriphaga and B. impatiens adults were all suppressed after heat shock ≥36°C for 1 hr (Zhu et al, 2017).…”