Getting Schooled by Aphids

2019 in our neck of the woods was the Year of the Aphid. They are true bugs – with mouths designed to pierce and then suck the sugar-containing fluids from plant stems. In the process, injecting diseases that may kill their hosts directly to their circulatory systems. Worse – they bear their young alive – and hungry – so their populations multiply quickly.

We have never seen so many aphids on so many different species. Wendy (writing this post) is domesticating Chenopodium berlandieri, which is not normally attacked by pests that eat the leaves or seeds. Chenopodium berlandieri produces edible seeds that were cultivated in the U.S., and is in the same family as quinoa. But this year, the aphids attacked, and I wasn’t prepared for the intensity of the onslaught. We don’t use most chemical pesticides in the gardens, which leaves physical removal and mostly-safe pest controls like insecticidal soap. Both of which are not effective against aphids. They have small, soft bodies that cling to stems and leaves so you cannot remove them without damaging the plant. They don’t eat leaves, so the treatments one can use to manage leaf-eaters are ineffective.

Early in the year, the gang in the chenopod patch was healthy and happy and growing well. 

Then the aphids hit – reducing the final crop to the smallest yet.

Under natural conditions, healthy soils and diverse plant communities can help plants withstand attacks like this by keeping sugar levels up and immune defenses strong. But even in a healthy, well-functioning community, sometimes plants succumb to attack.

To work with plants in less-than-controlled environments (i.e. not in a greenhouse) is a series of lessons in everything the plants know and you don’t. This was a lesson in the kinds of variability that people cultivating Chenopodium plants might have experienced – when a high-yielding patch fails to yield due to something that happens once in a great while, and leaves no evidence.

You could fall back on other cultivated or gathered crops, right? 2019 would have smacked you down again. A cool and wet spring meant later planting for maize. Cool temperatures once the maize sprouted meant it was stuck in the 2-4 leaf stage for a couple weeks, it needs to grow faster than that. Yield was low because of the slow start, the frequent cloudy weather, and uneven distribution of rain. It was a great year for hickory nuts. Acorns did not have a good year, and if not food for people, they are food for game birds and animals.

The point is – variability in food procurement via cultivation and gathering depends on a multitude of factors. Some of which leave little evidence.

Better luck next year!

Wendy Munson-Scullin