Washington — The Martinsburg Monster is looking over your shoulder.
Translated, that means the annual American spring rite of income tax returns is nearing its April 15 climax when the 10 subsidiary Internal Revenue Service centers will turn the forms over to the master file at Martinsburg, W.Va.
The Treasury has arranged it that way. The pretty flowers in the front yard and the income tax returns come together.
Last year as the hyacinths blossomed the Internal Revenue Service received 94 ,018,266 individual income tax returns for the year 1980. When corporate business and other returns were added, the total came to 166,527,670. The most enormous self-participatory bookkeeping task in the world.
No other big nation puts such reliance on the individual taxpayer. The end product is a major part of the taxes that make government work. Individual income tax returns last year amounted to $332.9 billion. The results all went ultimately to Martinsburg. They are there now on tapes.
This year will be bigger.
The estimate for fiscal year 1982 is 95.7 million individual returns. These are the ones being composed now by taxpayers staying up late to get their Form 1040s in final shape. The dollar amount of returns may be smaller than last year because of the recession: a tentative estimate is $298.6 billion.
The juxtaposition of spring and income tax returns has long been noted ironically by observers. The art of the tax collector, it has been said, is ''to pluck the most feathers with the least squawk.'' Profound traits of human nature are revealed in this most intimate of relationships between government and taxpayer.
For example, taxpayers prefer to pay a little too much on the first income tax round so that when the return is scrutinized they will get a government overpayment check back rather than a dun for more money. Statistically, last year there were 71.3 million refunds, coming to a sizable $48.4 billion. Seven out of nine changes that the government makes in individual returns are refunds.
A feature at Martinsburg is the absence of paper. All the filing of returns is done on tapes and electronic ''chips'' where the taxpayer's economic life is reduced to thumb-nail size. Here is where the computation for this year updates the return of last year as a scanning device compares the two. If there is a glaring error, or anomaly, the machine prints out a letter, addresses it, and sends it off to the taxpayer. If there is no response a revenue officer is supposed to call.
Critics of the present system charge that it has reached a mind-boggling complexity. So said Philip M. Stern a generation ago in his book attacking tax loopholes, ''The Great Treasury Raid.'' Since then complexity has grown, with more loopholes, in the opinion of many.
Some reformers yearn for the original 1913 income tax, the first in peacetime. It was a short and simple code with comparatively low rates and few exceptions to them. In 1924, almost 60 years ago, Treasury Secretary Andrew W. Mellon told the Coolidge era: ''The prosperity of the middle classes depends on the good fortune and light taxes of the rich.'' Taxes have grown for everybody since then. For one more spring, as birds sing and flowers sprout, the American taxpayer tackles Form 1040 and worries about the Martinsburg Monster -- while thinking longingly, perhaps, of these lines from poet Robert Frost: ''Never ask of money spent Where the spender thinks it went Nobody was ever meant To remember or invent What he did with every cent.''