Competition between larvae of wheat bulb fly, delia coarctata (anthomyiidae), for winter wheat shoots in an insectary
1977
Newly hatched wheat bulb fly larvae were added to 32 wheat seedlings with one shoot and three to four leaves, in large pots in an outdoor insectary so that the numbers of available shoots per larva were 32, 16, 8, 2, 1 and 1/2. Competition for shoots between larvae, measured by the number of shoots attacked and the emergence of flies, occurred only when there was 1 or 1/2 shoot/larva. Fewer flies also emerged from shoots when the number available was one or less than one shoot/larva. In the field, egg numbers in autumn equal to or less than 5 times 10⁶/ha (2 times 10⁶/acre), suggest fewer than the expected carrying capacity of winter wheat growing at the usual plant population except in spots where the density is greater than average because of aggregation.
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