Persistence, Prevalence and Emergence Patterns of Pasture Tunnel Moth - Essay Example

The following are the 22 families under the order Lepidoptera found in New Zealand (Alphabetical List, 2012):

Batrachedridae

Choreutidae

Crambidae

Depressariidae

Elachistidae

Gelechiidae

Geometridae

Glyphipterigidae

Gracillariidae

Hepialidae

Micropterigidae

Mnesarchaeidae

Nepticulidae

Noctuidae

Nymphalidae

Oecophoridae

Plutellidae

Psychidae

Pterophoridae

Tineidae

Tortricidae

Yponomeutidae

The family Noctuidae, or the owlet moths, are not only numerous in species but also robust – and they are the largest family. They have hind wings of bright colors. They are usually flying at night. They also invade flowers as many are attracted to sugar and nectar. Moreover, their larvae are crop pests (Cutworm Moth, 2012).
Moths that are Pests in New Zealand
Some moth pests in New Zealand include the Porina moth, Codling moth, Oriental fruit moth, White Butterfly, Diamondback Moth, and the Potato Tuber Moth (Story: Insect pests of crops, 2012).

The Status of Philobota in Australia and in New Zealand
In Australia, the Philobota species of moth, or the pasture tunnel moths, are grass feeders (Moate et al., 2012). The so-called tunnel moths make a silk-lined tunnel and during nighttime or winter, the caterpillar of the tunnel moth gathers grass foliage and drags them back into their tunnels. The caterpillars are very small and maybe quote difficult to notice for they measure around 35 mm long-only and 3 mm across (New pasture pest, 2010). Pasture tunnel moths usually live in areas with higher rainfall, and they can cause significant damage to clovers, as well as annual and perennial grasses. The larvae are usually grey-colored in their bodies with blackheads.

The adult moth, on the other hand, is long and has a creamy-white color. The pasture tunnel moth usually causes the greatest damage during the months of July and August, during the rainy months, for rain has a great factor in stimulating this species of moth to feed more (Pasture tunnel moth, 2009). Moreover, the pasture tunnel moth affects cereal crops (Perry et al., 2011).
The first time that Philobota species were identified in New Zealand was in February 2010 at the Ruakura Research Center in Hamilton, New Zealand. The migrant species are actually native to Australia, of which there are around 400 species, and where a number of these species are regarded as “minor pests of pasture” because it merely feeds on grass such as tall fescue trials and perennial ryegrass (Popay & Gunawardana, 2011).
In case a New Zealand resident sees pasture tunnel moths, then they should immediately contact MAF Biosecurity New Zealand (New pasture pest, 2010).

Philobota Investigation
Aim of the Study
The aim for the project is to determine the emergence patterns of the Philobota moth, as well as to know the possible factors that cause these emergence patterns and to know the location of the tunnels used by the Philobota larvae.
Method

In order to conduct the experiment, we searched for the tunnels constructed by the Philobota larvae in the vegetation at AgResearch. We set up light traps or boxes with light and counted and identified the moths that were caught in the light traps.

With the light traps, there are relatively more moths caught before and after the wet night on Oct. 19 compared to other days. There are 8, 4 and 10 moths caught during the 3 days before Oct. 19, and 8, 10, and 13 moths caught in the light trap during the 3 days after Oct. 19. It seems that rainfall also makes the moths favor the light trap more or makes them search for the light. Since there is no specific time when the moths were caught, then it cannot be determined whether daytime or nighttime affects the moth’s attraction towards the light.

Moreover, based on data gathered, the number of moths also increased before and after a very wet night like the one on Oct. 19. The total number of moths caught from Oct. 16, 17 and 18 are 11, 4, and 11 respectively, with 8 on Oct. 19. After this, 12, 15 and 14 months are caught on Oct. 21, 22 and 23 respectively. It, therefore, seems that rainfall favors the emergence of the Philobota moths.

Conclusion
Based on the data gathered, the moths seem to be attracted to the light before and after a wet night. Moreover, using the same data, one can conclude that more moths emerge before and after a wet night. It, therefore, seems that rainfall has a positive factor in the emergence of the Philobota moths.