Targeted control of the saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae), and the benefits of good control of this pest to winter wheat yield

Abstract

The trials showed that insecticide applications needed to be synchronised with H. marginata flight peaks and to target the egg hatching period. They also revealed that insecticides applied to coincide with the first flight could, in humid conditions, also reach the larvae close to the soil surface, prior to their pupation.

A review of the biology, ecology and control of saddle gall midge,Haplodiplosis marginata(Diptera: Cecidomyiidae) with a focus on phenological forecasting

“…Estimates suggest that when the percentage of infested wheat stems reaches 70%, losses of 2.2 t ha −1 could occur (Skuhravá & Skuhravý, 2014). A recent study in Belgium showed a correlation between number of galls and yield loss in winter wheat, in the most severe case yields fell by 191 kg ha −1 (0.191 t ha −1 ) for every increase of 100 galls per 100 stems (Censier et al, 2016). Past outbreaks of saddle gall midge in the UK have resulted in losses of 0.6 t ha −1 (Woodville, 1968).…”

“…Thresholds based on gall number are of limited use in pest management, however, as control measures are likely to be ineffective at this stage. It is acknowledged that the actual damage caused depends on many factors such as crop type, growth stage and weather conditions (De Clercq & D'Herde, 1972;Censier et al 2016).…”

“…Foliar applications of organophosphates such as malathion and dimethoate applied to the crop have shown some efficacy against eggs and newly-hatched larvae of H. marginata on wheat in Romania (Popov et al, 1998); and in the UK chlorpyrifos effectively reduced numbers of larvae and galls in wheat when applied at the visible flag leaf stage (Zadoks GS 37) (Roberts et al, 2014). Control has also been achieved with pyrethroids such as alpha-cypermethrin (Popov et al, 1998), and with deltamethrin, lambda-cyhalothrin and tau-fluvalinate on winter wheat (Censier et al, 2012;Ellis et al, 2014;Censier et al, 2016).…”

“…Censier et al (2012) found that treating the crop with pyrethroid insecticides twice with a two week interval resulted in 75-87% efficacy based on reductions in the percentage of attacked stems and mean gall number per stem. In a further study the authors recommended treating the crop to coincide with peak adult flight (Censier et al, 2016). The authors, however, acknowledged that phenological monitoring was essential in order to synchronise applications with vulnerable life stages (Censier et al, 2016).…”

“…In a further study the authors recommended treating the crop to coincide with peak adult flight (Censier et al, 2016). The authors, however, acknowledged that phenological monitoring was essential in order to synchronise applications with vulnerable life stages (Censier et al, 2016). Ellis et al (2014) reported that chemical controls applied at the start of adult emergence resulted in the lowest yield loss, although treatments applied 7-10 days post emergence or when the first eggs were seen also reduced midge infestation.…”