Preliminary tests to validate the effectiveness of the Inpest pheromone dispenser patch
Special breeding centre for Plodia interpunctella.
Monitoring traps are often used to catch certain species of stored product insect pests and in these traps a pheromone attractant is used to lure the insects. Once attracted, a sticky board or bucket captures the insect. In the case of stored product moths, the pheromones are sex attractants which attract only males of the pest species. The pheromone TDDA ((Z,E)-9,11-tetradecadienyl acetate) is a shared pheromone component of several stored product moth pests, typically referred to as Ephestia / Plodia species. This means a single pheromone dispenser can be used to monitor and detect several moth pest species including the Mediterranean Flour Moth (Ephestia kuehniella); the Cacao Moth or Tobacco Moth (Ephestia elutella), Almond moth (E. cautella) and the Indian meal moth (Plodia interpunctella).
In 2016, GEA developed an automatic production process for a new design of pheromone dispenser; a small (33mm x 21mm), very thin and lightweight fabric patch which would be easy for pest controllers to use and apply. The following summarises the tests that were conducted by GEA using the TDDA molecule to monitor food moths in general and in particular Plodia interpunctella and Ephestia kuehniella. This work covers only preliminary testing of the dispenser. These initial tests will be followed up in more detail, in particular testing the new dispenser in the field.
P. interpunctella is known to be more sensitive to TDDA and detects an ambient concentration ten times lower than E. kuehniella. When preparing pheromone dispensers aimed at more than one species of moth, the correct dose of the molecule must be loaded onto the dispenser to ensure that it remains effective for sufficient time and that the monitoring devices are activated immediately, thus avoiding emission peaks that could disorientate members of the more sensitive species.
For the purposes of evaluating the product, the behaviour of P. interpunctella at the beginning of the dispenser’s life and that of E. kuehniella at the end, is critical.
Laboratory evaluation
Easy Trap activated with TDDA pheromone patch for Plodia interpunctella
The tests were carried out in an empty, air-conditioned room (L x W x H = 520 x 300 x 260 cm) at 26.5°c +/- 2°c; rh 40–60%, with a central window on the shorter side. The trap (diamond or pagoda-shaped trap with a sticky liner), loaded with an InPEST pheromone patch for moths, was suspended approximately 170 cm above the ground and 120 cm from the wall and window. The dimensions of the test room are considerably smaller than the ideal pheromone coverage volume and it was recognised that this could contribute to the disorientation of moths when there are pheromone peaks.
The test began 12 hours after the trap was installed. Three to seven day old moths (a mixed population of males and females) were released from the shorter side of the room, opposite the window and trap. The release was made directly from a glass test tube used to collect the moth from the breeding chambers. The sex ratio was 50:50; the males therefore made up approximately half of the total population released. However, a test sample of the population raised under the same breeding conditions showed a higher percentage of females, around 65%.
This is an extract of the full article published in International Pest Control – January/February 2018 issue.
Read full article online on page 38
Author: Dr Marco Caimi*
*Expert in Entomology & Pest Management, InPest, GEA Srl, 20019 Settimo Milanese, Milan, Italy
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Category: Public health
